If you can read this ad, you're not using our software!

Actually the floating i-frame ads I think are the worst. They float around the window, and offer no means to close them (click anywhere on them, and they gotcha). Or a lot of sites when you navigate the site, they will randomly take you to a page with a big add banner on it, offering you a link to continue to the page you wanted to go to in the first place. @_X